Flash: Basic button actionscript

Hi,

I have created several button which have a rollover/rollout state using a rewind movieclip action:

stop();

this.onEnterFrame = function(){
if(rewind == true){
prevFrame();
}
}

this.onRollOver = function(){
rewind = false;
play();
}

this.onRollOut = function(){
rewind = true;
}

This works perfectly when an instance of the movie clip is place on the stage, also when I make the instance a button or create a button and place the clip in side it again works fine, however when I add any basic script such as:

on (press) {
gotoAndStop;
}

To take it to a frame label in the current scene the simple jump to frame action and the movie clip stop working…any ideas?

Cheers